engleski

Metal(loid)s accumulation and oxidative stress responses in brown trout under the influence of wastewater in a karst catchment

Besides estimating metal exposure in the dynamic river medium, risk assessment usually involves biological responses of aquatic organisms, that reflect long-term changes in the environment. Therefore, the impact of industrial and municipal effluents in the Krka River was estimated in the spring of 2021 by measuring (ICP-MS) Cd, Cu, Zn, Tl, Mn, Fe, Mo, As, Cs, Rb, K, Mg, Na, and Ca concentrations in the intestines of native fish species, brown trout (Salmo trutta Linnaeus, 1758), from the Krka River source (reference site, KRS), downstream from the wastewaters (KRK) and in the Krka National Park, Brljan Lake (KBL). In addition, the multi- biomarker approach included measurement (spectrophotometry) of biomarkers of oxidative stress (malondialdehyde, MDA) and antioxidant capacity (total glutathione, GSH ; catalase activity, CAT). Macroelements did not show statistically significant spatial differences, while elements such as Cu, Mn, and Zn were the highest in KRK, suggesting wastewater influence, which was confirmed by element concentrations in water, especially of those used in industry. Exceptions, although not always significant, were the highest concentrations of Mo in fish from KBL and of Cd, Cs, Tl, and Rb in fish from KRS. Significantly higher MDA concentrations in fish from KBL and KRK compared to the reference site pointed to oxidative stress, which was confirmed by the need of enhanced levels of both antioxidants (GSH and CAT) at these two sites. Evident effects on the biota, even in the national park, indicated potential risks to the protected area and emphasized the need for continuous and rigorous monitoring.

oxidative stress ; fish ; environmental contamination ; ICP MS

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